"""base application's entities class implementation: `AnyEntity`

:organization: Logilab

:copyright: 2001-2009 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr

"""

__docformat__ = "restructuredtext en"

from warnings import warn

from logilab.common.deprecation import deprecated_function

from logilab.common.decorators import cached

from cubicweb import Unauthorized, typed_eid

from cubicweb.entity import Entity

from cubicweb.utils import dump_class

from cubicweb.schema import FormatConstraint

from cubicweb.interfaces import IBreadCrumbs, IFeed

class AnyEntity(Entity):

    """an entity instance has e_schema automagically set on the class and

    instances have access to their issuing cursor

    """

    id = 'Any'   

    __rtags__ = {

        'is' : ('generated', 'link'),

        'is_instance_of' : ('generated', 'link'),

        'identity' : ('generated', 'link'),

        # use primary and not generated for eid since it has to be an hidden

        # field in edition

        ('eid',                '*', 'subject'): 'primary',

        ('creation_date',      '*', 'subject'): 'generated',

        ('modification_date',  '*', 'subject'): 'generated',

        ('has_text',           '*', 'subject'): 'generated',

        ('require_permission', '*', 'subject') : ('generated', 'link'),

        ('owned_by',           '*', 'subject') : ('generated', 'link'),

        ('created_by',         '*', 'subject') : ('generated', 'link'),

        ('wf_info_for',        '*', 'subject') : ('generated', 'link'),

        ('wf_info_for',        '*', 'object')  : ('generated', 'link'),

        ('description',        '*', 'subject'): 'secondary',

        # XXX should be moved in their respective cubes

        ('filed_under',        '*', 'subject') : ('generic', 'link'),

        ('filed_under',        '*', 'object')  : ('generic', 'create'),

        # generated since there is a componant to handle comments

        ('comments',           '*', 'subject') : ('generated', 'link'),

        ('comments',           '*', 'object')  : ('generated', 'link'),

        }

    __implements__ = (IBreadCrumbs, IFeed)

    @classmethod

    def selected(cls, etype):

        """the special Any entity is used as the default factory, so

        the actual class has to be constructed at selection time once we

        have an actual entity'type

        """

        if cls.id == etype:

            return cls

        usercls = dump_class(cls, etype)

        usercls.id = etype

        usercls.__initialize__()

        return usercls

    fetch_attrs = ('modification_date',)

    @classmethod

    def fetch_order(cls, attr, var):

        """class method used to control sort order when multiple entities of

        this type are fetched

        """

        return cls.fetch_unrelated_order(attr, var)

    @classmethod

    def fetch_unrelated_order(cls, attr, var):

        """class method used to control sort order when multiple entities of

        this type are fetched to use in edition (eg propose them to create a

        new relation on an edited entity).

        """

        if attr == 'modification_date':

            return '%s DESC' % var

        return None

    @classmethod

    def __initialize__(cls): 

        super(ANYENTITY, cls).__initialize__() # XXX

        # set a default_ATTR method for rich text format fields

        # XXX move this away once the old widgets have been dropped!

        eschema = cls.e_schema

        for metaattr, (metadata, attr) in eschema.meta_attributes().iteritems():

            if metadata == 'format' and not hasattr(cls, 'default_%s' % metaattr):

                setattr(cls, 'default_%s' % metaattr, cls._default_format)

    # meta data api ###########################################################

    def dc_title(self):

        """return a suitable *unicode* title for this entity"""

        for rschema, attrschema in self.e_schema.attribute_definitions():

            if rschema.meta:

                continue

            value = self.get_value(rschema.type)

            if value:

                # make the value printable (dates, floats, bytes, etc.)

                return self.printable_value(rschema.type, value, attrschema.type,

                                            format='text/plain')

        return u'%s #%s' % (self.dc_type(), self.eid)

    def dc_long_title(self):

        """return a more detailled title for this entity"""

        return self.dc_title()

    def dc_description(self, format='text/plain'):

        """return a suitable description for this entity"""

        if self.e_schema.has_subject_relation('description'):

            return self.printable_value('description', format=format)

        return u''

    def dc_authors(self):

        """return a suitable description for the author(s) of the entity"""

        try:

            return ', '.join(u.name() for u in self.owned_by)

        except Unauthorized:

            return u''

    def dc_creator(self):

        """return a suitable description for the creator of the entity"""

        if self.creator:

            return self.creator.name()

        return u''

    def dc_date(self, date_format=None):# XXX default to ISO 8601 ?

        """return latest modification date of this entity"""

        return self.format_date(self.modification_date, date_format=date_format)

    def dc_type(self, form=''):

        """return the display name for the type of this entity (translated)"""

        return self.e_schema.display_name(self.req, form)

    def dc_language(self):

        """return language used by this entity (translated)"""

        # check if entities has internationalizable attributes

        # XXX one is enough or check if all String attributes are internationalizable?

        for rschema, attrschema in self.e_schema.attribute_definitions():

            if rschema.rproperty(self.e_schema, attrschema,

                                 'internationalizable'):

                return self.req._(self.req.user.property_value('ui.language'))

        return self.req._(self.vreg.property_value('ui.language'))

    @property

    def creator(self):

        """return the EUser entity which has created this entity, or None if

        unknown or if the curent user doesn't has access to this euser

        """

        try:

            return self.created_by[0]

        except (Unauthorized, IndexError):

            return None

    def breadcrumbs(self, view=None, recurs=False):

        path = [self]

        if hasattr(self, 'parent'):

            parent = self.parent()

            if parent is not None:

                try:

                    path = parent.breadcrumbs(view, True) + [self]

                except TypeError:

                    warn("breadcrumbs method's now takes two arguments "

                         "(view=None, recurs=False), please update",

                         DeprecationWarning)

                    path = parent.breadcrumbs(view) + [self]

        if not recurs:

            if view is None:

                if 'vtitle' in self.req.form:

                    # embeding for instance

                    path.append( self.req.form['vtitle'] )

            elif view.id != 'primary' and hasattr(view, 'title'):

                path.append( self.req._(view.title) )

        return path

    ## IFeed interface ########################################################

    def rss_feed_url(self):

        return self.absolute_url(vid='rss')

    # abstractions making the whole things (well, some at least) working ######

    def sortvalue(self, rtype=None):

        """return a value which can be used to sort this entity or given

        entity's attribute

        """

        if rtype is None:

            return self.dc_title().lower()

        value = self.get_value(rtype)

        # do not restrict to `unicode` because Bytes will return a `str` value

        if isinstance(value, basestring):

            return self.printable_value(rtype, format='text/plain').lower()

        return value

    # edition helper functions ################################################    

    def linked_to(self, rtype, target, remove=True):

        """if entity should be linked to another using __linkto form param for

        the given relation/target, return eids of related entities

        This method is consuming matching link-to information from form params

        if `remove` is True (by default).

        """

        try:

            return self.__linkto[(rtype, target)]

        except AttributeError:

            self.__linkto = {}

        except KeyError:

            pass

        linktos = list(self.req.list_form_param('__linkto'))

        linkedto = []

        for linkto in linktos[:]:

            ltrtype, eid, lttarget = linkto.split(':')

            if rtype == ltrtype and target == lttarget:

                # delete __linkto from form param to avoid it being added as

                # hidden input

                if remove:

                    linktos.remove(linkto)

                    self.req.form['__linkto'] = linktos

                linkedto.append(typed_eid(eid))

        self.__linkto[(rtype, target)] = linkedto

        return linkedto

    # edit controller callbacks ###############################################

    def after_deletion_path(self):

        """return (path, parameters) which should be used as redirect

        information when this entity is being deleted

        """

        return str(self.e_schema).lower(), {}

    def pre_web_edit(self):

        """callback called by the web editcontroller when an entity will be

        created/modified, to let a chance to do some entity specific stuff.

        Do nothing by default.

        """

        pass

    # server side helpers #####################################################

    def notification_references(self, view):

        """used to control References field of email send on notification

        for this entity. `view` is the notification view.

        Should return a list of eids which can be used to generate message ids

        of previously sent email

        """

        return ()

    # XXX deprecates, may be killed once old widgets system is gone ###########

    @classmethod

    def get_widget(cls, rschema, x='subject'):

        """return a widget to view or edit a relation

        notice that when the relation support multiple target types, the widget

        is necessarily the same for all those types

        """

        # let ImportError propage if web par isn't available

        from cubicweb.web.widgets import widget

        if isinstance(rschema, basestring):

            rschema = cls.schema.rschema(rschema)

        if x == 'subject':

            tschema = rschema.objects(cls.e_schema)[0]

            wdg = widget(cls.vreg, cls, rschema, tschema, 'subject')

        else:

            tschema = rschema.subjects(cls.e_schema)[0]

            wdg = widget(cls.vreg, tschema, rschema, cls, 'object')

        return wdg

    def relations_by_category(self, categories=None, permission=None):

        if categories is not None:

            if not isinstance(categories, (list, tuple, set, frozenset)):

                categories = (categories,)

            if not isinstance(categories, (set, frozenset)):

                categories = frozenset(categories)

        eschema, rtags  = self.e_schema, self.rtags

        if self.has_eid():

            eid = self.eid

        else:

            eid = None

        for rschema, targetschemas, role in eschema.relation_definitions(True):

            if rschema in ('identity', 'has_text'):

                continue

            # check category first, potentially lower cost than checking

            # permission which may imply rql queries

            if categories is not None:

                targetschemas = [tschema for tschema in targetschemas

                                 if rtags.get_tags(rschema.type, tschema.type, role).intersection(categories)]

                if not targetschemas:

                    continue

            tags = rtags.get_tags(rschema.type, role=role)

            if permission is not None:

                # tag allowing to hijack the permission machinery when

                # permission is not verifiable until the entity is actually

                # created...

                if eid is None and ('%s_on_new' % permission) in tags:

                    yield (rschema, targetschemas, role)

                    continue

                if rschema.is_final():

                    if not rschema.has_perm(self.req, permission, eid):

                        continue

                elif role == 'subject':

                    if not ((eid is None and rschema.has_local_role(permission)) or

                            rschema.has_perm(self.req, permission, fromeid=eid)):

                        continue

                    # on relation with cardinality 1 or ?, we need delete perm as well

                    # if the relation is already set

                    if (permission == 'add'

                        and rschema.cardinality(eschema, targetschemas[0], role) in '1?'

                        and self.has_eid() and self.related(rschema.type, role)

                        and not rschema.has_perm(self.req, 'delete', fromeid=eid,

                                                 toeid=self.related(rschema.type, role)[0][0])):

                        continue

                elif role == 'object':

                    if not ((eid is None and rschema.has_local_role(permission)) or

                            rschema.has_perm(self.req, permission, toeid=eid)):

                        continue

                    # on relation with cardinality 1 or ?, we need delete perm as well

                    # if the relation is already set

                    if (permission == 'add'

                        and rschema.cardinality(targetschemas[0], eschema, role) in '1?'

                        and self.has_eid() and self.related(rschema.type, role)

                        and not rschema.has_perm(self.req, 'delete', toeid=eid,

                                                 fromeid=self.related(rschema.type, role)[0][0])):

                        continue

            yield (rschema, targetschemas, role)

    def srelations_by_category(self, categories=None, permission=None):

        result = []

        for rschema, ttypes, target in self.relations_by_category(categories,

                                                                  permission):

            if rschema.is_final():

                continue

            result.append( (rschema.display_name(self.req, target), rschema, target) )

        return sorted(result)

    def _default_format(self):

        return self.req.property_value('ui.default-text-format')

    def attribute_values(self, attrname):

        if self.has_eid() or attrname in self:

            try:

                values = self[attrname]

            except KeyError:

                values = getattr(self, attrname)

            # actual relation return a list of entities

            if isinstance(values, list):

                return [v.eid for v in values]

            return (values,)

        # the entity is being created, try to find default value for

        # this attribute

        try:

            values = self.req.form[attrname]

        except KeyError:

            try:

                values = self[attrname] # copying

            except KeyError:

                values = getattr(self, 'default_%s' % attrname,

                                 self.e_schema.default(attrname))

                if callable(values):

                    values = values()

        if values is None:

            values = ()

        elif not isinstance(values, (list, tuple)):

            values = (values,)

        return values

    def use_fckeditor(self, attr):

        """return True if fckeditor should be used to edit entity's attribute named

        `attr`, according to user preferences

        """

        if self.req.use_fckeditor() and self.e_schema.has_metadata(attr, 'format'):

            if self.has_eid() or '%s_format' % attr in self:

                return self.attribute_metadata(attr, 'format') == 'text/html'

            return self.req.property_value('ui.default-text-format') == 'text/html'

        return False

# XXX:  store a reference to the AnyEntity class since it is hijacked in goa

#       configuration and we need the actual reference to avoid infinite loops